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,IMPROVED TOOL-HOLDER FOR PLANING MACHINES.' l

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TO ALL WHOM IT MAY CONCERNE l Be it known that I, CHARLES HALL, of the city, county, and State oi'l New York, have inventedcertain new and-useful improvements in Tool-Holders for Planing Machines for planing metals; and-I do hereby declare that the following isa full, clear, and exact descriptio`n of my invention, reference being-had to theaeconrpanying drawings, in whichv n I Figure 1 represents a'face view ofthe tool-holder and appurtenances of a planing machincwith my improvements embodied therein. v

Figure 2 represents an end view of the same.

Figure 3 represents a. tranversesection of the same; and y Figure l represents views of a pair of tools suitable for use in the machine.

Planing' machines are constructed to impart a reciprocating motion either to the work or to thetool. The toolis constructed with but onecutting edge, and the tool-holder is generally pivoted to its support so as to hold the tool stationary only when the work is being moved -towhrd the cutting edge of the tool, leavingit free to move away from the work when the latter is moved toward its back, or, in vcase of a travelling tool-holder, when .the back of the tool is moved toward the work. Such machines, therefore, cut only when the carriage holding thevwork or tool is moving in one direction, and the time occupied in returning or retrograding the carriage previous to making a new cut is lost. Planers have been devised to obviate this defect by using two tool-holders, set back to back, and also by causing the same tool-holder to tu`rn half round upon a vertical axis at each stroke of the carriage; but these modes require greater complexity in the machinery than the ordinary mode, and for that or some other reason have not come "into general use. Planers have also been d evised with a tool stock vibrating upon a single central line, and holdingra double-edged tool, but the mechanism for determining the movement of the tool stock lhas been defective, and they have not come into general use. The object of my invention is toenable the tool of' the planer to operate with certainty and yaccuracy at each stroke of the carriage without increasing the complexity of the'machine; and to this end my 'invention consists of 'the combination of the tool st ock with its support by slots and pins or their equivalents, in such manner that vthe tool stock is permitted -to move a limited distance (in the line of movementf the carrage,) in two opposite directions, so that at each stroke of the carriagev one cutting edge of the tool or tools used is therebyr thrown out of its plane of operation, and a reverse cutting edge is thrown into its plane of operation.

`The mode in which I prefer to carry this invention into'eil`ect, when the work is moved along by the table ofthe planer, is represented in the annexcddrawings. In this example the to'ol stock A is a rectangular box, which is mounted upon a support or rest B; this rest is pivoted upona base, C, which is arranged to slide in the usual manner in the upright guides, a a, of a tool carriage, D, and is controlled by an upright feed-screw, I; The tool carriage D also is'arranged to slide in the usual manner transversely to the planer upon the guides e e, of the cross-slide E, which isV supported in the usual manner 4upon the standards of the frame of the planer. As, however, such standards, and 'the'v -frame and table or carriage for the work, and the other mechanism of the planer form no part of my invention, and may be constructed in any of the usual modes, I do not deem it neces= sary to describe them. The tool rest B is clamped to its bed in the usual manner by a clamp'escrew, c. The tool stock is net iixed rigidly to the tool rest B, but is held laterally between cheeks, ci 2, and is arranged to vibrate a limited distance in the line of 'movement of the work, and in the directions indicated by the arrowsff in g. 3. For this purpose, each cheekA cl of the tool' rest, is perforated with three slots, gg z, the upper two being oval in a vertical direction, and the lower one being curved horizontally. Moreover the tool stock is fitted at each side with three pins, s s 7', which are received in the said slots. This mode of connecting' tne tool stock yand tool rest permits the lower end of the former to move from a central position in either direction until the pins come in contact with the ends of the slots. The upper pins s a are placed at equal distances each side of the central lineof the tool in the tool stock, and the lower pinr is placed in that central line. The tool may be a double-headed tool with two cutting edges, as shown at iigs. 2 und 3, or two single-edged tools with their edges pointing in opposite directions, as represented at g. 4, may be placed side by side in the tool stock A, which is provided with set-screws t t t t, to secure the tools in their places. When a planer fitted with such a tool stock is in operation, the table carrying the work to be pla-ned is moved to and fro beneath the tool stock in the directions of the arrows ff', iig. 3, and the tool stock hangs in a c entral position when the tool is not acting upon the work, When the work is moved in the dir'ection of thearrowf, and is thereby borneagainst the cutting edge c of the tool J, the tool stock yielding to the pressure moves in the direction of the arrow as far as the slots permit, thereby holding the tool in the proper position, asindicated by the red lines Jl, for one of its cutting edges to operate. The tool remains in this .position until the work has been carried past it, when, as the pressure ceases, the tool resumes its central position; but, when by the return movement of the table, the Work is removed in the direction ofthe other arrow f, and` is thereby borne againt lthe other cutting edge 7c of the tool, the tool stock, yielding to the pressure, moves in Vthe direction opposite to that in which it moved during the preceding stroke of the tble, until 'such movemept `is stopped again hy the slots y h, thereby holding the toolin theposition indicated by the redlines J2, for its other cuttingedge to operate; and the tool retains this position until the workis carried past it, when, as the pressure is removed, it again resumes its central position. l

From the drawings and the foregoing description it willbc'perceived that the tool cuts in both directions, and that the vibration of the tool stock to bring one cutting 'edge into operation lifts thel otherout of its plane of operation so that it becomes inoperative for the time. It will also be perceived that when the tool stock turns from its central position in thc direction of the: arrowf, it turns upon the pins s as a centre, and when it turns-in the opposite direction from its central'position it turns upon the pins s as'a centre. In'either case the cutting edge of the tool is lower 'in the-'central position when the work first vstrikes it, than it'is in its cutting position, hence the tool cannot fail to bite into and act upon the'work even when taking a -iine cut. If the tool be so formed that both its cutting edges lic in the same longitudinal plane when .in operation, yand are 'then at the same distance from the table of the carriage, the feed motion of th;` tool should be operated atcach stroke of the table; but if'th tool be so ground that oneof its edges cuts in a diiferent line from the other, then the feed motion may be operatedfat the termination of each two strokes as is customary. This latter modeof grinding and feeding the tool permits one of its edges to be used for roughing, and the other for .iinishing, which I consider to be a goodmode of operating. 'If two single edge tools aretopbe used, they may be clamped in the tool stock, side by side, with their edges pointing in opposite directions, and one may be used to rough the work,

and the other to finish it, or both may be set to work equally. p

What I`claim as my invention, and desire to secure by Letters Patent, i's- The combination of the tool stock of a planer, with its-support or restby means substantially as above set iorth, so that the tool stock can move a limited distance in two directions in the line of cutting, whereby two opposite cutting edges may be alternately brought into yoperation and held there.

In testimony whereof I have hereunto set my hand this 24th day of May, 1866.

CHARLES HALL.

Witnesses:

E. S. RENwroK, W. L. BENNEM. 

